[color=mediumslateblue]I don't remember Tapirmon from the English version very well, so I don't know how the attack was intended to be. But for the sake of the story, you could say that because he is a rookie Digimon his attack would not be as powerful as an Ultimate (based on the level-game aspect present).

EDIT: I believe Double's character used a card to achieve the Ultimate attack.[/color]